1. Field of the Invention
The present invention relates to a method of enhancing command executing performance of a disc drive, and more particularly, to a method of enhancing read and write performances of a disc drive by utilizing a linked list called a command group for efficiently integrating a plurality of commands together, and by relieving starvation of the plurality of commands with the aid of the command group.
2. Description of the Prior Art
Please refer to FIG. 1, which is a related art diagram illustrating the distribution of a plurality of commands executing by a disc drive to a disc 102. As illustrated in FIG. 1, there is a plurality of commands that will be executed on three different areas 104, 106, and 108 of the disc 102, where the commands A0, A1, A2, A3, A4, and A5 are executed on the first area 104, the commands V0, V1, and V2 are executed on the second area 106, and the commands S0, S1, S2, and S3 are executed on the third area 108. The command sequence (A0, V0, V1, V2, A1, A2, S0, S1, A3, A4, A5, S2, S3) for indicating the order of executing the commands on the disc is also shown in FIG. 1. When executing two consecutive commands in different area, a seeking process is needed for seeking the starting address for executing the following commands. According to the command sequence illustrated on FIG. 1, six seeking processes are required when executing said command sequence, where a first seek is for seeking the beginning address for executing command A0 at the beginning, a second seek is generated between the executions of the commands A0 and V0, a third seek is generated between the executions of the commands V2 and A1, a fourth seek is generated between the executions of the commands A2 and S0, a fifth seek is generated between the executions of the commands S1 and A3, and a sixth seek is generated between the executions of the commands A5 and S2.
However, involving more seeking process when executing the command sequence increases time consumption.
In summary, for read and write commands on a disc and in a command sequence, switched execution between read and write commands lead to a large amount of seeks, and further lead to a large time consumption of the disc drive in accessing the disc.